Incidence of Metopism in Adult Skulls from Southeast Brazil

Research Article

Austin J Anat. 2016; 3(3): 1059.

Incidence of Metopism in Adult Skulls from Southeast Brazil

Bernardes FM¹, Giroldo AM¹, Roquette AGD² and Marques KV³*

¹Medical School of Federal University of Uberlandia, Brazil

²Service of Neurosurgery from Clinical Hospital of Federal University of Uberlandia, Brazil

³Department of Surgery, Medical School of Federal University of Uberlandia, Brazil

*Corresponding author: Marques KV, Department of Surgery, Medical School of Federal University of Uberlandia, Pedro Quirino St, Uberlandia, Minas Gerais, Brazil

Received: October 04, 2016; Accepted: December 21, 2016; Published: December 30, 2016


Objectives: The aim of this study was to determine the incidence of persistence of metopic suture in human skulls of Brazil Southeastern and compare with literature.

Methods: A collection of 42 human skulls from Nucleus of Morphology was used in order to identify persistent metopic suture. The subjects were catalogued and documented with photographs. Craniometrics points were used in order to obtain dimensions of metopic suture.

Results: An incidence of 4.76% of metopism was obtained in analyzed skulls, which all were classified as complete metopic sutures, with a linear pattern intercalated with serrated and interdigitating pattern.

Conclusion: Although its low incidence, knowing metopic sutures’ anatomy and its correlation to imaging exams is essential to establish different diagnosis in trauma medical care and practice.

Keywords: Frontal bone; Cranial sutures; Anatomy; Neuroanatomy


The anatomical characterization of the metopic suture has been well described in the literature with emphasis on its clinical relevance in diagnosis and surgical options for craniosynotosis [1]. The metopic suture (also known as the medial frontal suture) extending from the nasofrontal suture (nasion) superiorly along the midline to bregma runs exactly through the median line of the frontal bone [2]. Its timing of closure is still controversial. Previous studies suggest that the closure of the metopic suture normally starts from birth to 3 months of age and is generally fused completely at the age of one or two years [3-5], by the fourth year of age [6], between the fifth or sixth year [7-9], or by the seventh year [10] by eight years of age [11-13] or by tenth year of age [14]. However, it is widely accepted closing around the age of 2 years olds [13]. A persistent metopic suture in adult skull is relatively rare. The persistence of metopic suture into adulthood is called as metopism [15-16]. The anatomy of the metopic suture has been reported in many populations such as Lebanese [10], Indian [17-19], Anatolian [20], Iranian [21], Nigerian [9]; and Brazilian [22- 24]. Racial variations in the incidence of metopic sutures and shapes have been observed and reported in the literature [25].

Knowing the anatomy patterns of metopic suture in skulls is important for radiologists and neurosurgeons to differ trauma in the frontlines, differing it from frontal bone’s fracture or even sagittal sutures. Beyond that, it is equally important to paleodemography and forensic medicine professionals establish parameters of frontal bone’s fracture and metopic suture. The aim of this study was to determine the persistence of the suture metopic in human skulls of South Eastern Brazilian and compare it with previous literature.

Materials and Methods

A total of 42 human dry skulls were analyzed for persistency of metopic suture, in the Laboratory of Human Anatomy from Medical School of Federal University of Uberlandia, a southeastern institution. Specimens were obtained in accordance with Law 8501 of November 30th, 1992, which rules the use of unclaimed cadavers for teaching and research purposes in medical schools. Data from specimens, including age and gender were not assessed and none of them showed visible abnormalities.

Classification of the metopic suture

A macroscopic observation of shape and main characteristics of the sample was made and documented in records and photographs. Skulls with metopic suture can be divided in three specific types: type one, normal, without metopic suture; type two, complete metopic suture, which extends from the nasion to the bregma uninterruptedly; and type three, with incomplete metopic suture. They can also be divided in groups according to shape and pattern: linear, ‘U’ shaped and ‘V’ shaped) [9]. In (Figure 1) we show different classifications for metopic suture.